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Currently, almost all major hard foam industries have completed the conversion to ODP zero foaming agents, and most rely on hcfc-141b as the primary replacement for the currently banned perchlorofluorocarbons (CFCs).

Current major blowing agents include hydrofluorocarbons (HFCS) - primarily hfc-245fa ($4/lb) and, to a lesser extent, hfc-134a ($2/lb). They are usually high in water and can co-foam with carbon dioxide. The second main blowing agents are hydrocarbons - isopentane, n-pentane and cyclopentane (50￠to 60￠/lb). There is also a newer Foam Supplies Ecomate based on methyl formate that can be supplied separately or with blends at the same price range as pentane. The Ecomate is said to have insulation between the high-performance hfc-245fa and the pentane.

Under the trade name Enovate 3000, hfc-245fa (North America {TodayHot} manufacturer is Honeywell International, which is a leader in perfusion product insulation (refrigerators and water heaters) and in hard spray foam insulation for walls, roofs, containers and hot springs.

In the more cost-sensitive field of polyisocyanate (PIR) panel insulation for roofing, pentane has been switched.

An exception to the overall shift is the metal-faced foam sheet, which still allows the use of lower ODP HCFC22 and 142b, which the federal environmental protection agency (EPA) aims to end by 2010. Industry statistics still argue that although hfc-245fa is also a candidate, the industry has changed significantly with the use of pentane in general.

At this meeting, Foam Supplies reported that its Ecomate product, which has been used for thermal insulation of water dispensers and large coolers for the past four years, is now being developed for new USES in perfusion areas such as the production of door panels. The company has worked with some large polyol and surfactant suppliers to identify potential applications in other hard foam industries, such as replacing pentane in plates; It is used for spraying foam which concerns the cost of hfc-245fa. Perhaps even more conservative electronics.

According to the company, Ecomate has high solubility, low molecular weight, high foaming efficiency and low volatility, and the dosage can be lower than hfc-245fa and hcfc-141b. For example, a 15 percent hcfc-141b system might require only 5 to 6 percent Ecomate for the same density.

Regardless of the foaming agent used, understanding what happens during the process is of interest to the foaming formula designer. "Figuring out how much of the foaming agent is in the polymer matrix and how much remains in the foam is critical to optimizing the formulation and determining the nature of the foam," explains Mary Bogdan, chief scientist at Enovate's technical services and applications group, honeywell's research lab in Buffalo, n.y.

The honeywell researchers determined that there is no single analytical technique that can easily quantify the distribution of foaming agents in polyurethane foam. Therefore, they are developing a practical and economical method to determine the amount of foaming agent in the polymer and foam gas, as well as the amount of foaming agent emitted during the foaming reaction.